Field of the Invention
The invention relates to a multiplexer configuration having the following characteristics:
a) at least one first and one second group of transistors each including one first, one second and at least one third transistor; PA1 b) emitters of the transistors of the same group being connected to one another and each being connected through a respective current source to a terminal for a first supply potential; PA1 c) collectors of the first transistors of each group being connected to one another and being connected through a first resistor to a terminal for a second supply potential; PA1 d) a collector-side terminal of the first resistor being connected to an output terminal; PA1 e) base terminals of the second transistors of each group each being an input terminal for one data signal; PA1 f) base terminals of the third transistors of each group each being a terminal for one respective selection signal; and PA1 g) the selection signals being signals complementary to one another.
Such multiplexer configurations are known from German Patent DE 40 30 631 C2. Each current switch includes a reference transistor having a base at which a fixed reference potential is present. If a proper signal-to-noise level is to be adhered to, the signal level rise must not drop below a minimum rise (400 mV). That also limits the maximum operating speed, since the parasitic collector-to-substrate capacitances must undergo a charge reversal over the entire signal level rise.